Blood oxygenating apparatus



Nov. 27, 1962 AKE SENNING ETAL 3,065,748

BLOOD OXYGENATING APPARATUS Filed June 7, 1955 INVENTORS d fKE SEN/V/N ATTOR EYS United States The present invention refers to an apparatus intended for use in extracorporeal circulation of blood, for instance in diseases with impaired heart or lung function or in operations on the heart or the lungs. Devices of this type are previously known, in which admixture of oxygen bubbles with the blood occurs, whereupon unabsorbed oxygen is removed from the blood, which is then returned to the patient. On the other, it is previously known to oxygenize blood by spreading it on a rigid body in an oxygen atmosphere.

The blood oxygenating apparatus according to the present invention is characterized by an arrangement for spreading the blood on a rigid body in an oxygen-containing gaseous atmosphere, the arrangement comprising a rotatable cylinder of a perforated material.

According to an embodiment of the invention, the apparatus comprises the combination of an arrangement for the admixture of oxygen bubbles with the arrangement for spreading the blood, the combination being such that the blood passes first through the arrangement for the admixture of oxygen bubbles and then through the arrangement for spreading of the blood.

In the oxygenation of blood through the admixture of small oxygen bubbles in large number with the blood, it is easy to achieve a large area of contact between the oxygen and the blood so that a device of this type is very effective as far as the absorption of oxygen in the blood is concerned. However, great difficulties are encountered in removing the carbonic acid released simultaneously with the oxygen absorption. If a surplus of oxygen is supplied large enough to make the partial pressure of the carbonic acid in the bubbles appreciably lower than the carbonic acid tension in the blood, which is the condition for the carbonic acid to be removed from the blood, the gas bubbles, when leaving the blood, cause violent foaming so as to make it practically impossible to reduce all the foam to homogeneous blood. A continual loss of blood can therefore not be avoided.

The invention will be described in the following with reference to the accompanying drawing showing an embodiment of an apparatus according to the invention.

In the embodiment shown, it is assumed that blood issuing from a patient is supplied at the arrow 1. The blood flows through the tube 2, in which oxygen bubbles are admixed, and on to a container 3, which is filled with chips or wool or the like 4 of some indifferent substance, such as Teflon. The chips are treated with some agency, such as the so called antifoam, which reduces the surface tension. From the container 4 the blood flows into a vessel 5 containing a rigid body, on which the blood is spread so as to cause as intimate contact as possible thereof with the gas mixture in the vessel. The rigid body is designated by 6 and can suitably consist of a rotatable cylinder, which is partly immersed in fill Free

the blood and is made of perforated material, such as Wire netting or a perforated foil, which may preferably consist of a plastic. From the vessel 5 the blood flows into a tube 7, containing chips of a similar kind as the container 3, whereupon it is pumped by a pump 9 through a tube 8 and is brought through a tube 10 back to the patient, as indicated by the arrow 11. Oxygen is supplied to the tube 12 and passes a membrane controlled regulating valve 13, whereupon it flows through a porous tube 14 placed in the tube 2. The oxygen then leaves the tube 14 in the form of bubbles, which flow upwards in the tube 2 and mingle with the blood so as to provide effective oxygenation thereof. The valve 13 is controlled through a lever 15 by a membrane 16, which is responsive to the pressure in the tube 10. In this manner a control of the amount of oxygen supplied through the tube 12 is obtained in response to the amount of blood being in circulation.

The function of the described arrangement will be clear from the above. In the tube 2 there occurs an intense oxygenation of the blood, as a result of which there is however a large amount of oxygen bubbles left in the blood. These are to a great extent removed in the passage through the container 3 and bubbles that may possibly not be removed there disappear during the spread ing of the blood on the rotating rigid body 6 occurring in the vessel 5. To the vessel 5 is applied, as indicated in the drawing, through a tube 16 a mixture of oxygen and nitrous oxide (laughing-gas). In the embodiment shown, it was assumed that laughing-gas is administered as a narcotic. It is then supplied to the vessel 5, in which it can dissolve in the blood. At the same time, it fulfills another function, namely that of decreasing the partial pressure of the oxygen in the vessel, so that diffusion of the content of the oxygen bubbles out of the blood is facilitated. The gas mixture supplied leaves the vessel 5 through an outlet tube 17, through which also flows off the carbon dioxide expelled from the blood. The blood issuing from the vessel 5 passes through the tube 7, where possibly retained nests of oxygen bubbles are removed, and then flows on through the tube 3 to the pump 9', which fulfills the function that would normally be performed by the patients heart, and drives the blood through the tube 10 back into the circulatory system.

What is claimed is:

A blood oxygenating apparatus comprising a tube means for admixing oxygen bubbles with blood, a container having a portion thereof filled with chips and having in another portion a pool to collect said admixed bubbles and blood therein, said container further including a vessel portion containing a rotatable rigid cylindrical body of perforated material which is partially immersed in said pool, for spreading the blood and forming a de-foamed film of blood thereon, a connection from the admixing tube means to the container, gas inlet means connected to the container for allowing the introduction of oxygen and nitrous oxide into the container for dissolving into the blood and for decreasing the partial pressure of the oxygen in the vessel portion, and gas outlet means connected to the container for allowing removal of carbonic gas from the container.

(References on following page) 3365/2728 3 References Cited in the file of this patent Gimbel et al.: An Oxygenator for Use in a Heart- UNETED STATES PATENTS Lung Apparatus, American College of Surgeons Surgical Forum 1952, Saunders and Co., Philadelphia, Pa, 21652331 Chesler Sept- 1953 pp. 154-157. (Copy available in Army Medical Library, 2,712,897 Kusserow July 12, 1955 5 Washington, DC, and Division 55.) 2,887,107 Wehrli May 19, 1959 Karlson: Pump-Oxygenator to Supplant the Heart and Lungs for Brief Periods, Surgery 29, No. 5, 678-696, May 1951, pages 685-687 relied on. (Scientific Library.)

Bjork: An Artificial Heart or Cardiopulmonary Machine, The Lancet, September 25, 1948, pp. 491-493. (Scientific Library.)

OTHER REFERENCES Clark et al.: Dispersion Oxygenation, Proceedings of the Society for Experimental Biology and Medicine, vol. 74, 1950, pp. 268-271 (page 269 relied on). (Available in Scientific Library.) 

